1. Field of the Invention
This invention pertains to sanding devices, and in particular to a light weight pole sander for use in sanding dry wall that is attached to a vacuum hose to be vacuum driven and to remove sanding dust off of a wall surface and pull that dust into a vacuum canister.
2. Prior Art
The present invention contemplates a new and improved vacuum driven sander that is appropriate for mounting onto a hollow tube or pole to be manually moved over a sheet rock wall to function as a dry wall sander, providing an oscillating sanding section that mounts a sheet of sanding material. The sanding section of the sander is operated by a vacuum driven turbine to smooth a dry wall surface, creating dust that is pulled through the turning turbine blades and into the hollow tube that a vacuum hose is connected to, to vent into a vacuum canister.
Heretofore, a number of sanding tools incorporating vacuum devices for removal of sanded particles and for transporting them through a connected vacuum hose to a collection vessel have been employed. For example a number of U.S. utility patents to Mehrer U.S. Pat. No. 4,062,152; to Marton U.S. Pat. No. 4,184,291; to Romine U.S. Pat. No. 4,697,389; to Paterson U.S. Pat. No. 5,007,206; to Sanchez, et al. U.S. Pat. No. 5,193,313; to Brown U.S. Pat. No. 5,283,988; to Matchuk U.S. Pat. No. 5,605,600; and to Brown U.S. Pat. No. 5,624,305, all show examples of manual sanding devices whereto is connected a vacuum hose for drawing dust off from a surface being sanded. Similarly, a number of electric motor driven devices that connect through a hose to a vacuum or suction device have been developed and examples of such are shown in U.S. Patents to Davies U.S. Pat. No. 1,800,341; to Jones U.S. Pat. No. 3,468,076; to Hutchins U.S. Pat. No. 3,785,092; to Hutchins U.S. Pat. No. 4,052,420; to Matechuk U.S. Pat. No. 4,782,632; to Flacheneck, et al. U.S. Pat. No. 4,905,420; to Fushiya et al. U.S. Pat. No. 5,018,314; to Chu, et al. U.S. Pat. No. 5,228,224; to Smith U.S. Pat. No. 5,384,984; to Hutchins U.S. Pat. No. 5,582,541; to Heidelberger U.S. Pat. No. 5,595,530; to Everts, et al. U.S. Pat. No. 5,637,034; and in Design Patents to Taylor U.S. Pat. No. Des. 375,885; to Gildersleeve et al. U.S. Pat. No. Des. 392,861; to Fushiya et al. U.S. Pat. No. Des. 326,398; to Morey et al. U.S. Pat. No. Des 351,976; and to Stiles U.S. Pat. No. Des. 353,313. None of which sanding devices, however, provide a sanding device that includes a vacuum driven oscillating sanding disk that, additionally, provides for removal of sanded particles from the work surface through an attached vacuum hose that is like that of the invention. Similar to the invention, U. S. Patents to Brenner U.S. Pat. No. 3,722,147; to Rodowsky, Jr. et al. U.S. Pat. No. 4,399,638; to Brenner U.S. Pat. No. 3,722,147; and to Marton U.S. Pat. No. 4,616,449, shown sanding devices where an oscillating plate mounting a sheet of sand paper is air driven by a vacuum flow and also provides for removal of sanding dust off from a work surface and the moving of that collected dust through a vacuum hose into a collection container. With the patent to Rodowsky, Jr. et al., U.S. Pat. No. 4,399,638 believed to be the closest to the invention. However, while, like the invention, the ""638 patent provides a turbine blade that is turned by a vacuum air flow passed over the turbine blades to operate an oscillating plate whereto a section of sanding material is attached and will pull sanding dust therethrough, the turbine bearings of the ""638 patent are exposed to that vacuum air flow with entrained sanding dust particles tending to collect in the turbine bearings, greatly limiting bearing life and, accordingly, the life of the device. Whereas, the invention is arranged to provide the presence of a positive or greater than vacuum pressure across its turbine bearing assembly, prohibiting the dust contaminated vacuum air flow from traveling into which bearing assembly, greatly lengthening the life of the bearings, and further allows for passing lubricants therethrough to lubricate the bearing assembly bearings, greatly improving upon earlier vacuum sanding devices, such as the ""638 patent.
Additionally, as improvements over the prior art, the invention includes a balanced split-air intake that provides a balanced driving force onto the turbine blades by drawing essentially equal air flows from both sides of the sander that also improves upon the entrainment of dust and contaminants in the air flows as are passed through the sander. Also, the turbine itself is improvement in that it incorporates a split design where the top and bottom turbine sections are not symmetrical, with the lower turbine section having the greater height to allow the bearings and bearing supports to be conveniently fitted inside the turbine mounting in the sander housing providing a turbine housing profile that is shorter than former sanders turbines and has a lower center of gravity as compared to earlier sanders. Further, the invention provides an improved pole coupling assembly whereby, the pole angle to the sander top surface can be conveniently changed and that angle can be maintained while the sander is moved up and down or along a wall surface.
It is a principal object of the present invention to provide a vacuum air driven turbine operated sander for attachment to a conventional vacuum line wherethrough an air flow is pulled, with the air turning the turbine that is, in turn, connected to turn an eccentric that is fitted into a bearing mounted in a sanding plate to oscillate that plate, thereby moving an attached sheet of sanding material in an orbital path over a surface to be sanded.
Another object of the present invention is to provide a vacuum driven sander that includes turbine blades and turbine bearing assembly for turning in a housing wherein a passage is provided for passing a flow of clean air at ambient pressure into the bearing assembly, providing cooling thereto, and discouraging the vacuum flow wherein sanding dust is entrained from passing to the bearings of the bearing assembly and providing for passing a lubricant therethrough into the bearing assembly, greatly extending the bearing life and the life of the device.
Another object of the present invention is to provide a vacuum driven sander having a low profile provided by an incorporation of a turbine, as the device motive power source, that is formed from two non-symmetrical halves and includes, as a bearing assembly, a pair of bearing and bearing supports, that are to be fitted into a stanchion formed within the sander housing to contain turbine section, with the turbine top and bottom sections to be fitted together to close off which turbine section in the sander housing.
Still another object of the present invention is to provide a vacuum sander having a balanced split-air intake where air is drawn from opposite sides of the housing through the turbine, efficiently picking up and entraining dust particles in the flows as are generated by oscillating movement of the sanding pad that is provided by turbine rotation.
Still another object of the present invention is to provide a vacuum sander that incorporates a hollow tube connected to the sander body to be conveniently adjusted at its mounting to the body top surface to change the sander pad surface angle to the wall being sanded, and provides for connection of a vacuum tube as a pole to the hollow tube end opposite to the sander body.
Still another object of the present invention is to provide a vacuum driven sander that is light in weight and convenient to connect to a vacuum hose to both turn an oscillating sanding plate or pad and to draw collected dust therethrough for passage to a collection container.
The present invention is in a new and improved vacuum air flow air driven oscillating sander that includes a bent hollow tube that connects to a hollow pole whereon the sander is mounted and is connected to pass the vacuum air flow therethrough and into a vacuum hose to vent that flow into a collection container. The bent hollow tube is arranged to turn axially at is connection to the top of the sander body at a collar that has a number of radially spaced cavities formed therein that selectively receive stub pivots fitted therein that are formed to extend oppositely from a ball end of the bent hollow tube. A cap having a center hole therein is provided to fit over the bent tube and is for turning onto the collar to maintain coupling of the stub pivots in the selected radially spaced cavities, allowing the bent hollow tube to be turned relative to the collar end and to be locked in place. So arranged, the angle of the sander forms to a wall can be adjusted by a repositioning of the stub pivots in the radially spaced cavities and turning the cap onto the collar.
Further unique to the invention, the sander includes a turbine that is mounted by a bearing assembly onto a stanchion located within a sander housing, and provides, by a passage formed through the housing into a bearing assembly cavity located within the stanchion, for a flow of ambient air to the bearings during operation and precludes contamination of the bearing assembly by dust entrained in the vacuum flow that has passed over the sanded surface, greatly extending bearing life over earlier air driven sanders that have exposed their turbine bearings to the dust filled vacuum air flow.
Additionally, the sander body of the invention exhibits a significantly reduced profile by an incorporation of a split design turbine that allows the bearing assembly to be conveniently fitted into and assembled in a bearing cavity in a shanchion formed in the housing. The construction of the turbine as a split design provides two turbine sections, with a lesser height upper section arranged to cap over the greater height lower section, simplifying mounting of the turbine bearing assembly in the bearing assembly cavity prior to fitting the assembled turbine thereto. The turbine is turned by passage of the vacuum air flow there through that is first passed through balanced air intakes where air is pulled across the surface being sanded and into the housing opposite ends, applying a balanced driving force to drive the turbine. The turbine, at its lower end, is connected through an eccentric to oscillate a sanding pad whereto a section of sanding material is releasably attached.
The sanding pad is formed as a plate, and the entire sander is assembled and held together by four (4) screws that are each turned through spiders attached to corners of the inner surface of the plate that are turned into the housing lid or top, maintaining the sander in its assembled state.
Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.